Richard Bogren, Gill, Daniel J. | 8/2/2018 8:35:48 PM
By Dan Gill
LSU AgCenter Horticulturist
(08/03/18) Gardeners who move to Louisiana from other parts of the country are often amazed at how fast landscapes develop and mature. With our long, warm growing season and generous rainfall, rapid growth is the result. This is a mixed blessing.
As we move into summer, it is important for gardeners to keep an eye on flower beds, shrubs and vines in the landscape, looking for plants that are growing too large or beds that become too crowded. Plants may grow larger than expected and start crowding other plants. Tall plants shade out or fall over onto smaller plants. Plants spread into areas where they were not intended to grow. Vines develop a mind of their own and take off in totally unexpected directions. Without the guiding hand of the gardener, the resulting chaos can lead to disaster — particularly if things are allowed to grow unchecked for an extended period.
Some of these problems can be avoided by becoming familiar with a plant before you plant it into the landscape. In particular, you should always know what the mature size of a plant will be. If you do not know the mature size of a plant, it can result in planting trees, shrubs, vines and perennials that will eventually become too large for their location.
Another problem is planting beds with shrubs or bedding plants spaced too close together. Gardeners often want newly planted beds to look full and lush as soon as they are planted, without taking into consideration the growth the plants will make. A newly planted bed with plants properly spaced should not look full.
Even in a well-planned landscape, though, the controlling influence of the gardener is always important. The most useful methods for dealing with especially enthusiastic plants are pruning, supporting and digging out or installing barriers to prevent unwanted spreading.
A snip in time
When it comes to pruning, it’s good to remember that it is better to prune lightly, occasionally, as needed, than to allow a plant to get way overgrown and then have to cut it back severely. I almost always carry a pair of pruners with me when I walk through my garden. A few judicious snips here and there help keep more-vigorous plants from overwhelming their less-vigorous neighbors. Done properly and regularly, this type of pruning is not even noticeable.
Pruning can be used to control the size or shape of a plant or influence how it grows. Lightly trimming back a plant such as a coleus, hibiscus or impatiens every now and then will keep it more compact and bushy. Cutting wild shoots that occasionally occur on shrubs will keep them more shapely and attractive. And, of course, removing or shortening growth that is covering nearby plants will help those plants to stay healthy.
Means of support
Staking or otherwise supporting plants is done to keep plants from leaning or falling over onto nearby plants. It helps the tall plant look better and obviously benefits the plants that would otherwise be covered. I suggest you use bamboo or plastic-covered metal stakes. With the constant presence of termites, wooden stakes are almost certain to become infested. They are also more prone to decay. The stake should be tall enough to do the job, but not be too obvious. If young children will be playing around the garden, however, the stakes should be taller than they are to reduce the possibility of injury. You should also be careful when bending over in beds where plants have been staked.
Stakes may simply be placed in such a way that the plant is supported by leaning up against it, or it may be necessary to tie the plant to the stake. Green, brown or black twine or plastic ties will be less obvious than other colors. Make sure you tie both the lower and upper parts of the plant to the stake to provide proper support.
Another less noticeable and useful way to support plants involves the use of a brick or stone and works remarkably well. Straighten the plant up into the desired position, and then wedge a brick or stone at the base. You will find that the support at the base will usually hold the plant more upright without being visible. If this doesn’t work, a stake might be necessary.
Other techniques for support include tying twine in a loop all the way around a plant, using a wire cage (best done early in the growing season allowing the plant to grow into it), tying a plant to a sturdier, nearby plant or using one of the commercially available support systems, of which there are many.
Many perennials and tropicals spread by underground rhizomes, some fast and some slow. If growth shows up outside the area you have allotted for that plant, promptly dig out the unwanted growth. Or dig up the whole clump and divide it. This can be done annually to control aggressive spreaders. Extra divisions can be replanted somewhere else, potted up and given to friends or discarded.
Barriers extending at least 8 to 12 inches down into the ground around aggressive spreaders can help keep them under control. A plant can be planted into the ground in a container with its bottom cut out to limit or slow spreading.
Use your imagination and deal with each situation creatively. The important thing is to promptly and regularly deal with these situations where control is necessary. We gardeners often think of ourselves as designers and cultivators. But don’t forget, we must also often play the role of mediators and referees.
Shrubs that are planted too close together and that grow too tall can distract from the look of a house and limit views from windows. Photo by Rick Bogren/LSU AgCenter
Out-of-control vines can grow quickly in south Louisiana, even into trees. Photo by Eric Bogren
Vines can overtake fences if they're not regularly controlled. Photo by Eric Bogren